The present inventions relate generally to container return systems and, more particularly, to container pick and return systems that permit the efficient delivery of containers and their contents to an access aisle for easy unloading and the automatic return of empty containers to a loading aisle. The present inventions are particularly advantageous when used in assembly line applications, such as the automotive industry. However, they are equally pertinent to a wide variety of other applications.
In assembly line applications, for example, an important consideration is the constant supply of parts, typically of a wide variety of sizes, shapes and weights, to the assembly line worker. Ease of access to these parts, the removal of empty parts containers, and the re-supply of parts are also important considerations to the overall efficiency of the process. Any delay in the flow of parts, any difficulty in access to parts or any difficulty in removing empty containers can lead to inefficiencies in the entire assembly line process.
Systems capable of accommodating these considerations are shown and described in U.S. Pat. No. 5,567,103 to Konstant and U.S. Pat. No. 5,642,976 to Konstant, both entitled "Unloading Device" (the "Konstant patents") (both of which are incorporated herein by reference). The Konstant patents teach, among other things, container unloading systems that selectively and automatically cycle carts carrying unit loads, such as containers or parts bins, to the front (or access aisle) of the system where the load is held at an angle for unloading. The system then cycles (returns) the carts and unloaded unit containers to the rear of the system (loading aisle) for re-loading and re-use. In other such systems, pallets or bins ride on pairs of parallel flow rails and carry the unit loads to the access aisle for use. The empty unit loads may then be selectively and automatically returned to the rear of the system for reloading.
Other available systems require the use of air cylinders, solenoids and motors to cycle unit loads. One such system is the Roll 'n Lift system by Creative Storage Systems, Inc. of Kennesaw, Ga. These devices utilize relatively complex electronics and pneumatics to present a pallet and return unloaded pallets and the like. Such systems suffer from, among other things, their expense, complexity and high maintenance.
In some applications, it is desirable to eliminate the necessity of wheeled carts used to carry the unit loads. In this manner, there is greater flexibility of unit load size and systems costs, and associated maintenance and shipping costs, may be reduced. For similar reasons, it is also desirable to eliminate the need for and complexity of electronically controlled air cylinders, pneumatics and motors. It is also desirable to have an efficient and smooth system that can be effective with heavy loads and provide the gentle presentation of such loads.